If you want to use sealant, liquid laundry starch works well. I use it it my riding mower tires that pick up a lot puncture vines. I would find the leak first then decide how to repair it. It might be better to repair with a patch or a tube. sealants don't work well on tire beads, valve stems and larger holes. I got a nail in a rear tire of my Kubota , I put a plug in it as a temporary repair , that was 20 years ago. It doesn't leak, every time I would look at it I would think I need to patch that, now the tires are worn out and need to be replaced.