I use water washable resin and the end result is still sticky. The problem is the UV cure wasn't long enough.

If you don't have an ultraviolet light, curing it in the sun will do the same thing. The down side to sunlight is it takes longer and if only one side is exposed to the sun, it may warp. I use an ultraviolet light and a powered turntable. Cure time depends on the size of the part. 1/25 tires take about 4 - 5 minutes under a UV light, whereas they could take a couple of hours under sunlight.

If you do use IPA, try to use something on the high end. 99% preferably. 50% will work but it won't do near as good a job. You'll have to wash it a few times. And DON"T soak it for any length of time. Put some IPA in a container, put some gloves on, swish the part around in it, use an old brush if you want, then let the part air dry.

Once it's clean and dry, treat it like any other resin. Sand, fill, prime, paint as you usually would. As far as glue goes, I've used the brand name "Krazy" glue and dollar store super glue, both had good results. Regular model glue, Testors, Tamiya Extra Thin, etc., will not work.