Dude, I'm with you, I'm poor right now til I get back to work. You do not have to use the gel at all, but it sure helps.
Your shoot should be actively growing in order to root the best, it's the draw on the stems reserves after taking the cutting that force it to root. If the cutting wasn't hungry it would never root.
* for those too stoned* to assemble the bubbler/cloner, Just put your cuttings in some plastic cups with water and occasionaly top up the water or replace it.Nothing sophisticated or high tech here.
I say becouse we overcomplicate things.Cloning in a plain glass of water is an old method that does work.
Happy Growing ppl.