hidrogen peroxide is not flammable as far as I know, but it does supports burning, it definitely can cause skin "burns" when concentrated.. I guess you could use it for bleaching also?
@geezer: H2O2 is oxidizer, this is sth you might need at the end...
first you must reduce the the -S-S- bonds resulting in -SH HS- ... in this state a remodelling the form would have to take place and than at the end removing the reducing agent, maybe oxidizing as well (where peroxide can come into place) but take care that the oxidation won't damage the horn .. I think the best thing would be to ask an older hairdresser how they did it..
reducers that we use (in the lab) are eg B-mercaptoethanol, dithiotreithol, but these are extremely strong, toxic, cancerogenic (fumes also) and would not be a good choice,.. not to mention that the smell like ****** ..
when you do this stuff definitely take care of the fumes, take care of skin and eyes protection also, you are doing with high temps, pressure, aggressive chemicals (i guess) and high pressure (to some extent)!!