Some people here in Texas pour cheap vodka or everclear down the city water inlet, run it through all faucets, then blow everything out with compressed air. Even 10% alcohol remaining will push the freeze point of the mixture down to 25 degrees, and over 30%, no worries about freezing until near zero degrees Farenheit. Alcohol also has antiseptic properties. Plus, it won't kill you if you get a bit of it in your drinking water.
This is not a "real" way to winterize, and it definitely is riskier than using the pink stuff, but people in central TX do this on their boats with some success.
Of course, the toilet and sink/tub traps should get RV antifreeze poured down, as that takes very little time and does the job right.
I've even read reports about people winterizing with the el cheapo white wine with some success (it turns into a slush reportedly.) However, I don't feel daring enough to try that.
