According to internet sources, temperatures above 130F/55C kills dust mites. This need not take place in the wash phase, as almost all dryers reach or exceed that temperature. I don't know how well a dilution of iodine low enough not to stain would kill them or their eggs.
*I think* we got the whole 'boil wash' idea from hospitals. Which are trying to keep people from catching diseases they didn't come in with. IOW, other people's bugs. Yet hospitals are notorious places to get sick with things you didn't have to start with. Despite all their heroic measures.
OTOH, if your clothes and bedding didn't make you sick when you were using them, why would they make you sick after washing them? They're not 'other people's', they're YOURS or your immediate family's.
If one means commercial laundromat machines, run them empty through the hottest cycle with a heavy dose of sodium hypochlorite to kill 'other people's' bugs before putting YOUR stuff in. That in fact is what I do, now that I am reduced to living in an institution which prohibits private laundry machinery.