Oxy/PBW effective with cold water?

I just picked up two cornys that I want to clean really well. Will using PBW/Oxy and water from my outdoor hose (cold water) be effective for an overnight soak or should I try to use hot water?

Use hot water. It will work much better.

There are 3 factors (which you can control easily) that will impact your cleaners effectiveness:
Contact Time, Agitation and Temperature
If you go lower on one, you have to compensate with the others.

Use hot water with either and rinse with cold water.

Personally I boil about 3-4 gallons of water, and place the recommended amount of PBW (homemade - one 3lb container of oxiclean free and 1 bag of Red Devil TSP from Ace hardware) into my cornies, add water, and top off with hot tap water.

Soak overnight. In the morning the water is still pretty warm, about 85°-90°f I toss all the posts, o-rings, dip tubes and such in as well. In the morning, I scrub with a carboy/corny brush, and rinse, rinse, rinse, the hotter the water the better. I turn it upside down, let it dry during the day while I'm at work, and lube, sanitize, and reassemble when I get home.

Charge with 30psi to seal and I'm ready to fill next time I need it. I just spray the posts down with some sanitizer beforehand.

Cheers!

I have good luck with just taking off my shower head and fill them up from there. It really depend on how dirty they are.

I have the two cornys sitting in am Oxiclean solutions. These things smelled awful. I think they were sitting outside for a couple years. I may have to re-soak them again tonight.

Hot water might be better, but I soak my fermenters overnight with cold water and oxyclean from the garden hose every time and it does just fine.