Any runny oil, vegetable or mineral, or glycerine + some emulsifier? + filter through cheesecloth to remove impurities. Bear fat from bears who ate almost exclusively pine nuts stays liquid in the fridge, but it's easier or cheaper to just use vegetable oil.
Trailing scents for smaller mustelids don't make much sense, I think the smell should be concentrated directly at the set. If you've tracked their movement patterns (diurnal range tracking for instance) you know they move like the ball in a pinball machine, they just bounce around randomly moving along the most appealing areas, and check out promising spots, or sometimes dash between good areas through more open spaces. I've had plenty of time to try using lure for trailing scent when sable were uncooperative. Sometimes I'd just put a dab of lure on the edge of my ski, and usually when their path crossed mine, they'd stop, poop in my tracks and move on. On rare occasions they followed my tracks more closely (but even so, they didn't stay in my tracks the whole time) but they were exceptions rather than rules, it was always hungry big nonresident males, most likely long-distance travelers. I think drops of trailing scent will just confuse them and may ultimately cause them to lose interest, because they'll investigate the spot, find no food and leave rather than figure out that it's a sign leading somewhere. I think it's because they target voles that are scattered all over the place. Even when they chase bunnies, they zigzag freely rather than follow bunny trails until they establish visual contact. Canines and maybe guloes will follow the scent because they have the concept of "trail" (tracks left by big game or snowmachines = potential meal), but even so, a lump of bunny guts tied to a rope will probably work better than a squirtable lure?