What a day for royal commission junkies. Of the three currently in session, you could watch two at once today. News networks channel-surfed between both this morning, failing to capture anything exciting at either.

In Sydney, union bagman Ralph Blewitt sat in the dock of Dyson Heydon’s inquiry into union corruption in a preview of full hearings later this year (Blewitt was nabbed today while he’s in the country). Given the forensic analysis from the media into Blewitt, decades-old slush funds and the links to Julia Gillard, the union witch-hunt is unlikely to cast any new light.

In Brisbane, Crown spinner Mark Arbib took a break from managing James Packer’s police investigation to appear at the inquiry into the Labor government’s pink batts program, where he was probed about what role he had in the roll-out (not much, he said) and what he communicated to then-PM Kevin Rudd (very little, apparently). Rudd and the minister who was responsible, Peter Garrett, will appear later.

The toll of the insulation roll-out was significant: four installers died in a program that was certainly hurried and mismanaged. Rudd, particularly, has some serious questions to answer. What’s left of his reputation, at least, is at risk.

But the cost of royal commissions is rising, too. These latest two might deliver favourable headlines for the government, but they’re expensive fishing expeditions in the unlikely hope of political scalps. If they tell us what we already know — that unions have rotten elements, and governments botch policy implementation — what exactly will have been the point?