I've always used my shop vac (5hp Craftsman) to suck out the return lines, skimmer, pump basket reservoir, and chlorinator before the SWG. Has worked just fine for my 10 years of IG pool ownership. The only drawback is you have to empty the container, obviously. Just wanted to throw in another option for those that don't wish to buy an expensive air compressor or blower.

Hope this helps, Tony