Hi ritchieca and welcome to the forum. I think you're worrying about something that isn't going to be an issue for you. People go years and years using bleach without worrying about the salt and without doing a complete water change. My pool is in its 11th season with never draining. Poconos (fellow mod) is on his 14th year. There are many other who have been using bleach in their pools for many years longer than that with no worries about salt building up. In fact, some people (who don't even have a SWCG) deliberately add salt because they like the way the water feels.

Go with bleach. You won't regret it.

Again, welcome. Hope you enjoy being a part of our forum!