For what it's worth...I don't use anything. Just keep it clean...and
I've found that just keeping the serving well waxed works as well as anything.

On plastic rails...don't know.
Despite the as advertized "Teflon Impregnated"...hard anodozed surfaces are very slippery as the BowTech and Darton rail is.
Darton strings will live a VERY long life because of the light string to rail load.
Though I do have a Quad 400...as I noted I just keep the serving waxed...I really don't shoot it much so I kan't really comment on serving/string life.

Mike