I bought a Viet Nam Yanmar 2210D rebuild. Checking the transmission I found some water in the fluid. White contamination. I drained the Trans and the Hydraulic unit. Pulled the screen filter and cleaned it. There was not a ton of water contamination but at least I would estimate a pint of so. Top of the oil was still pretty clear bottom dregs white. Anyway, I would like to flush the trans to get what ever moisture and scum is clinging to the case walls. Not sure what I can put in there to clean it out. Gasoline? Methanol? MEK, Toluene. I was just going to fill it and drain it again not operate it. Just wanting to clean up the dregs before putting in new fluid. Any suggestions what I can use that will not screw it up? Thanks.