My opinion, no..
When you're done riding/racing, mix up a THICK batch of castor oil and gas, like 20:1...and purge it for a solid 4-5 minutes.
Or...you could pick up some of that uplon from klotz. It's an upper end lube that the 4 stroke guys mix in their methanol, but you can use it as a purge oil too. It cleans the methanol residue from the motor pretty well...