Soap water will work - but it's not the right way to do it - when the water evaps it leaves the soapy residue which will cause the vinyl adhesive to fail prematurely. The professional way is to dry apply or use of Rapid Tac or other approved application fluid.
3M Glass tape is the Sh*t! It is very expensive for the roll but I've had one roll for over a year. It comes in a 2" wide roll by 80' I usually split the two inches and cover both sides of my squeege and it lasts for some time.
Denatured Alcohol is what I use to pre wipe my surface - gets the grease and oils that can conflict with vinyl adhesives quite nicely.
And standard box or rags/towels works well for wipeing.
about the squeegee he asked me to try adding lam on it ...
well what do we know...
Lam won't work - depending on the lam type it might actually stick to itself. Avery's 1060 has a tendancy to want to stick to its surface to sruface...
You might also try strips of Nylon - I think its like a nylon patch kit or something because the nylon has an adhesive backer - cheaper and you can buy them at most any fabric stores but it doesn't hold up as nicely.
Since finding felt squeeges a few yeas ago, I hardly ever use a plastic one.
Sometimes they scratch a little, but it usually goes away.
If you drop it, make sure you clean all the grit off before using.
For the squeege there are sleeves to make it nicer to vinyl. We put the loop side of velcro on the edge too. And then there rae felt squeeges.