we use a product called "aqua-gel". seems to work better than the old "yellow-77", and evaporates rather than getting sticky and "gluey" like the yellow-77. i have had to pull out cables such as MCM 250-500 before, that had been originally pulled with yellow-77, and they were stuck inside the pipe like super-glue, sometimes, nearly ripping the conduit down, just to get them to budge a little.
