Medussa, you can DT with OneC; just put gobs on, cover with a plastic bag, and apply the heat. It works fantastically.
I have to say, though, after 1.5 years of CG, I can't DT with heat because I get overconditioned. I just put the gobs in, put the plastic bag on, and rinse through 30-45 minutes later.
When I do oil treatments, I leave it on overnight. But any heat and I'll be a soft poofy puff ball the next several days.
There's also Jessicurl's weekly DT, which is very powerful and CG friendly. It's definitely too much for my hair at this point, I don't ever really use it anymore, because even without heat it's too much.
Actually, now that I think of it, if you PM me I can send you some if you want. Jessicurl also does samples, so you can get a sample from them directly.