Many OTCs will make it worse, because they have artifical ingredients for color, scent, flavor, etc. that actually exacerbate the problem. You should use only pure vaseline to lubricate (and not a vasaline product with other ingredients, e.g. Vaseline intensive care).
And see my other posting about Lamprene. Some of the postings I'm reading sound a little wacky to me, although when I was suffering I would have tried anything with even a remote chance of working or endorsement from anyone.
I'm telling you, talk to your doctor about Lamprene. It's real medicine, it changed my life. Do yourself a favor and get some.