Tri-flow will not swell delrin at all and as slick as a delrin bolt is without it, one or two drops spread with your fingers will make it much more so. It is super effective on o-ringed bolts too. You want to use it sparingly to keep dirt collection to a minimum, but it is not too bad. On Intimidators, even with that big slot down the top of the body for the bolt pin grime does not collect horribly, but it WILL hold more dirt than a dry bolt will. Keep in mind that since 2003 I have used it on litterally hundreds of Intimidator bolts (bolts only as the Intimidator takes Dow55 on everything else), as well as all of my personal guns with no ill effects.
Find it at bicycle shops.