MAKOMIKE here's how you do it...
Take a small piece of rag.... Tie it to a piece of polypropylene electricians pull string...this stuff is very lightweight but very strong. Stuff it in the conduit...go to the other end and take a standard vacuum cleaner and stick it over as much of the piece of conduit as you can...if it leaks then wrap a rag around it. It will suck the line right thru the conduit right beside what's there...in about 4 seconds your done.
On new conduit you can use a "mouse" that ties to the line and sucks thru, this is how I do it, but if your thrifty you can save yourself alot of time and aggravation....I do this stuff all the time and I can pull a cable in a 1000' conduit in about 5 minutes flat
Works on T top legs too
As far as dish detergent for pull soap...use the electricians pull lube...it dries to powder and makes less of a mess later on. You shouldnt need it if you got a helper. If it feels like it's getting tight then pull back and you should be able to move through the tough spot if you pull without stopping.