is this a high enough percentage to to do a cake extraction...is the denatured a bad thing?

I'm not familiar with "cake extraction" off the top of my head so I can't comment on that.

Whether the denatured alcohol is usable or not depends on the denaturant. Methanol? Fine (as long as it's evaporated and you don't consume it at the end of the extraction). Denatonium? No good. Maybe you could link us to an MSDS (material safety data sheet) for the product in question?

unfortunatly, i dont live in the us and this is available to me in pharmacys where there is no msds...is there anyway to tell the differece without the sheet...here they use it like ipa for cuts and scrapes(strange huh?) if you've never tried the cake method...of all the extractions i've tried(many)...it was the easyest

Denatonium will come over in an a/b so i would avoid it. can you not get acetone? acetone is nice and volatile and dissolves lots of things.

taste a tiny bit, you should be able to taste the denatonium, its super bitter. If its denatured with methanol then it should taste kinda sweet and volatile, more so than straight ethanol.

as that i evaporate all alchol before starting the extraction...would the denatorium evaporate(probally not)...and 5ml of methanol is fatal...sure i should taste it?