Is there anything that could be deemed more showbiz than a call for reform of the parliamentary committee system? With the possible exception of a treatise on some arcane area of contract law, Lost in Showbiz can think of no more appropriate material for this column, so let us proceed immediately to Tuesday's session of the Home Affairs select committee.

I do not know whether this troupe of high-minded MPs has yet commissioned stationery bearing the screamer "the most starfucking bunch of dullards this side of OK! magazine", but if not, I am happy to furnish them with the quote. Chaired by the odious Keith Vaz, whose advance towards the red benches appears to be as ineluctable as it is sensationally ill-deserved, the committee this week followed up its decision to call Amy Winehouse's father to discourse on the cocaine trade with an invitation to Russell Brand to address them on drug addiction. To substitute one genuine expert with a tabloid celebrity may be regarded as unfortunate; to do it twice begins to look like a clear strategy.

Any useful idiot even remotely tempted to begin arguing that, as a recovering addict, Brand is a worthy witness is hereby advised to stop being so bally silly. Lost in Showbiz hates to let daylight in on magic, but Brand is not there because of anything he might say. He is there because he will get Vaz and friends on the telly. It was the same with Mitch Winehouse, whose appearance (a couple of years before his daughter's death) was deemed sufficiently eye-catching by the news programmes to be worth featuring – just as the committee had calculated it would.

And so it proved with Brand. The only bright spot was that the news coverage was briefer than it might ordinarily have been. Alas, Brand's appearance before the committee was scheduled on the same day as James Murdoch's before the Leveson inquiry – suggesting my thrice-weekly sacrifices to Clash, the god of scheduling, have been looked upon favourably.

But if Russell's shtick is to your taste, there would have been much to delight you in his testimony, for instance his mini-riff when told the committee session was running out of time. "Time is infinite," he announced delightedly in the manner of a seven-year-old whose mother still praises him lavishly each time he does a number two. "We can't run out of time."

"You can tell what party they're in from their questions, innit!" he honked, laughing uproariously throughout at his own gags. They were interspersed with occasional cutaways to Vaz, who smiled on with all the indulgent authority of a man censured three times by parliamentary standards officials, yet somehow still in charge of a committee.

Alas, Vaz and the others have clearly decided to model their committee's shtick on US congressional hearings, which have been besmirched by the use of "expert" celebrity witnesses for decades. The real rot set in when, in 1985, the House agriculture committee tabled a hearing called "The Plight of the Family Farmer", and promptly called Jane Fonda, Sissy Spacek and Sally Field to testify on the basis that they had all played farm wives in movies. Politicians realised that this got their faces on the telly and, by 2002, things had degenerated to such a degree that Elmo from Sesame Street became the first fun-fur witness to testify on Capitol Hill.

Will this be Britain's fate, if nothing is done to curb the attention-seeking of Vaz and all those like him? The possibility seemed to suggest itself to the committee's David Winnick, who eventually pointed out: "It's not quite a variety show, Mr Brand."

"You're providing a little bit of variety though," retorted Russell, laughing even before he reached the punchline of this zinger. "Making it more like Dad's Army!"

Not enormously droll. Which is disappointing – after all, artless insults about Winnick can be very funny indeed. Lost in Showbiz always gives in to an involuntary giggle at the tale of Harold Wilson standing at the dispatch box and referring to Winnick as "the stupidest man in the House".

Of course, it should ring alarm bells that even a man of Winnick's intellect appeared to have worked out what was going on and was troubled by it. Yet the most telling aspect of both this guest spot and the Mitch Winehouse one before it was that not a single member of the committee was sufficiently respectful of the electorate to refuse to attend on the grounds that calling Brand was nothing more than an exercise in publicity-seeking.

MPs would do well to remember that stands can be taken. A few years ago, a US Senate committee called one Kevin Richardson to assist it in its inquiries into a controversial mining technique. Richardson's professional qualifications? He was in the Backstreet Boys. On the basis of his testimony, his expertise could be summarised as having seen a few of these mines from the window of a private jet. For one lawmaker, it was the line in the sand. Then Ohio Senator George Voinovich refused to attend the hearing in protest, declaring: "It's just a joke to think that this witness can provide members of the United States Senate with information on important geological and water quality issues. We're either serious about the issues or we are running a sideshow."

What do you reckon Keith Vaz is running? Needless to say, he is running it on your dime, as these things cost taxpayers' money, to say nothing of the parliamentary time that might be spent on something – anything – more worthwhile than promoting Keith Vaz. We can only await his next celebrity "expert" with resignation.