Anything that will remove stubborn paint without scrubbing is either:
way too evil to use at home
also going to damage the model
difficult / illegal to buy
or a combination of the above.
There are some 80s models out there painted in some god awful car primer that is next to impossible to shift chemically, especially a problem with preslotta stuff that I collect.
Please do not put acids on your models! They almost certainly won't touch paints of any sort, and will attack the model surface, as may strong alkalis.
Don't even joke about HF, I have 20 years lab experience and I refuse to work with it. And I happily work with cyanide every day, that's how horrid HF is.
I can get 98% of paint off 98% of models, but that involves industrial chemicals, industrial equipment and hard work. Only the latter of which is available in the home!
If you can't get them clean, send them to me and I'll throw the laboratory sink at them
Re: the book, you would sell 100 in minutes mate, surely! I would remove any risk by asking for pre-orders and a deposit before committing, Kickstarter style. No reason why it should only be for $100,000 projects after all!