I might stay away from the winter mixture as that stuff has calcium chloride or something similiar mixed in so you don't have to scrape the frost off your wind shield.

I don't mix my "what ever's the cheapest brand washer fluid" with isoprop alcohol. I do use the straight isoprop. to get out the rem oil or bore butter (which ever I used so my bore wouldn't rust in storage,) before the first shot. In another post I did detail my cleaning regime that works with 3fg 777 and makes the crud ring a none issue.

1. Soak a patch in washer fluid, and run it up and down with the bore brush, not a normal jag. If the fouling is light like most times I just get the brush wet and use that to break everything up.

2. Switch to a loading/general use jag and a dry patch to get all the broken up crud and dry the bore.

3. Using a stiff brush I clean the chamber side of the breech plug.

I truly believe that the whole crud ring thing is because people don't clean enough between shots. Unfortunatly for 777 it means you prettty much clean after each and every.