I have a DK2M with a Floyd Rose, and my frets have gotten really dirty. Can I take several strings off at once so i can clean the frets without messing up the tremolo? Also, what should I clean the frets with?
you are going to kill me but:

I don't think you can take off several strings at a time, plus that would be a pain in the ass. Just clean your board when you change strings next.

Maybe ask this in the FR Set Up sticky in EG.

I use .0000 steel wool on my frets once or twice a year. Going up and down the fretboard and following the grain of the wood. Maybe a bit of lemon oil for guitars. That is with a rosewood or similar type board.

Maple, just use a tooth brush and water.

it's a pain, but when you change strings next I would just take them all off at the same time, clean the guitar real nicely (body cleaner as well) and then spend the time to put on the new strings and set it all up.

Plus, the no oil on maple thing that mr. blah name about said is REALLY important. I'm not sure what a DK2M has, but I know a lot of jacksons have maple.
well just buy a freat cleaner of dunlop and clean it but dont take out all the strings
There is also a rumor that you should use spit and wool. The crazy thing is that it really works!