Lactobacillus is relatively easy to kill - it's probably floating around in your house right now, and your normal cleaning/sanitizing regimen is taking care of it. Make sure that the fermenter doesn't have any scratches or cracks that might make it hard to clean. Once it's clean, a few minutes of contact time using an acid sanitizer (pH <3) should be sufficient. Use it as an excuse to replace any vinyl tubing you use for transfers, just to be safe.
Brettanomyces is a different animal, so to speak. It tolerates very low pH levels, which is why it's so hard to eliminate. Multiple caustic-acid-steam cycles are the safest bet, but that's going to be pretty much impossible for a home brewer.