Agree with Keith, as getting the oil as dry as possible will have the knock on effect of requiring less catalyst for the conversion.
Since starting with ASM, the amount of glyc that I've got has reduced in line with the reduction in base amount, I used to get out a bit less than the amount of meth used when using NaOH, now, it's way less.
160ltrs of oil in and dried using the venturi, vented to atmosphere, glyc wash, then 24-25lts meth total. Glyc out is now around 16 ltrs.
I also get an increase in the bio out, around 170 after washing.