Unless you are old, have a terminal illness, or you are severely compromised physically, VSED is not going to work.
Many people here have tried it and failed. I don't think there is any evidence on this forum implying someone was successful with it.
As to the drugs - not sure if forcing your brain in to overdrive would be helpful - for me at least, it would make me obsessive about getting a drink of water.
If I was going to use drugs with VSED, I'd go with opioids and sedatives - at least you'd basically be asleep most the time if you have an ample supply. This effect would be the opposite of what you are suggesting.
What about dping vsed with cocaine or crystal meth?
I also wanted to add the only way to pull it off is if you are completely isolated and not around other people, because you will look horrible.
Don't mean to be a Debbie downer or anything, just trying to be realistic about what you are up against.