I've tried the "Perfect Victoria" I think the product was called but it has caused all kinds of problems with clothing.
What is the best bend fix product to buy for V4?
You're not going to find one that doesn't cause issues with clothing. If you're committed to the figure, the best solution is to get Dimension3d's Morphing Clothes and transfer the fixers into your clothing with it.
Are you using Transfer Active Morphs to apply the morphs to the clothes? That is not necessarily going to be a fix in all cases, but it should at least help.
Are you talking about "Perfect V4" from Renderosity? I am using the same product and I have no problems with it.
Here is my workflow for using it:
1. load "Perfect V4"
2. Turn off limits and turn off IK
3. Inject other morphs as needed (Base Morphs, Morphs++ etc.)
4. Apply clothing, hair and all you need.
5. Shape V4
6. Pose V4
7. as a last step inject the "Perfect V4" fixes!
This way I never had any problems. Some pokes with clothes are normal if the clothes do not have the morphs you use on V4, but that is normal. Most of the time a smoothing modifier on that piece of cloth cures the problem.