Third Party Grip that is water resistant?

I've been trying to research and see if any third party grip manufacturers tout their product as being able to retain a water seal for the battery compartment (5d2 grip specifically). The fact that I've had a difficult time finding one leads me to believe that it's pretty unlikely, but I figured I'd check with you guys and see if anybody is familiar with a brand.

Or are there any DIY solutions for adding a sealing gasket to a grip? I'm not a fan of using a plastic bag, and I don't see myself shooting often enough in inclement weather to really consider an OEM grip-- but I would also like to miss any shots if I don't have my 1d2 on me.

I don't think any grip available for 5dm2 would be water resistant as most normal grips, because of the battery insert, exposes the battery compartment of the 5dm2 to the elements

the WFT-E4IIA grip on the other hand, doesn't have the battery insert as it doesn't power the camera, so it might be more weather resistant

the other thing you could try is insulation or vinyl tape