Yes, Malic acid has a reputation for helping. I've read hundreds of posts, and have seen quite a few from people whose flushes didn't work, in which they also said they did not take apples or malic acid. (and there were also people whose flushes didn't work who DID take apple or malic, but not as many)
Here is one source that is very cheap:
(If this url doesn't work because it is so long, you can instead go to http://www.swansonvitamins.com and do a search for Malic) There are other sites that sell it too.