I don’t know about blow drying…I suspect wiping it on a towel would probably be enough to keep it rust free for the entirety of its useful life.
I tried some of those money saving razor tips. The only one that kind of makes sense is to strop your disposable razor on an old piece of jeans or even your forearm before each use (about 15–20 swipes tends to work). It helps to keep the edge in alignment so the blade will work better for a little longer.
Some people claim to be able to stretch a disposable razor out for 6 months by doing this. I found it to work for a bit, but even a honed edge will be crap if the blade is no longer sharp. 3–4 weeks seems to be the upper limit for me, outside of that and I think people are just fooling themselves that the blade is still sharp.
Screw that. I hate shaving enough as it is. Throwing a dull blade into the mix makes it intolerable. I’m more than happy to drop a hundred bucks a year or so on razors if it means I can use an ultra sharp one every single time.