Greetings
The memory foam will absorb some frequencies and can cut back on reflections.
You need to give it a try.
Maybe start in the corners, or first reflection points. I don’t think they will absorb the low low frequencies.
We all have to start somewhere. Hopefully you will eventually move up the food chain and acquire devices that are specifically made to treat audio rooms.
I have tried numerous absorption and diffuser devices over the years. The only DIY ones that remain in my room are the 20” tube traps that I built and the diffuser cones on the front wall.
The ones specifically manufactured for room acoustics works the best.
Give it a try, you got nothing to lose and maybe something to gain.
Joe Nies