Maybe try an alcohol based liquid rooting hormone? The alcohol helps keep things clean, and can stop clones from rot,mold,or mildew in higher humidity. Clonex and other rooting gels have worked for me, but I don't think it is worth the money. You could get some plain old cheap alcohol based liquid IBA rooting hormone, and see if you have better clone rates.
I also find rockwool to be the easiest medium to root into. Sometimes I use soil or soilless, but rockwool gets nearer to 100% of clones rooting.
