Extending and Hanging, Girth gains

I’m guessing I’m posting this mainly too ask for advice. I’m trying too focus my efforts on length, exclusively, and I’m seeing progress, there’s a small problem though. My length is increasing, but it’s slow as hell, and while I seem too have gained about a centimeter and a half in length, I’ve also gained a centimeter in girth. Is there a way too focus primarily on length instead until I want too increase my girth?