Should I try splits?

I've been practicing yin yoga and gravity yoga for a while I don't have much results and occasionally, my inner knee gets hurt. 2 days ago I found this website from elastic steel that focuses on strength and flexibilty training through YouTube. I tried some of his warmup exercises and I'm tempted to get his video. I'm still considering as I don't want it to end up as another waste of money. I still believe in yinyoga but I think I lack the warm ups and loosening exercises which yinyoga doesn't teach. I'm still considering. It would be so nice to be flexible and strong and destress by getting into a split or some position like straddle pose and rest and meditate like that. Should I or should I not? Please help me decide....