A lacrosse ball may be too hard.
I’d recommend using a yoga tune up ball.
If you are doing work and not seeing change you need to take another look at how you are approaching it.
Pro Episode # 21 – Pro-User Request Friday: Not Seeing The Change? You Need a Systems Approach.
Have you tried a session with a coach locally?
Here is info on scheduling a virtual session http://www.mobilitywod.com/consult/