@thomthom said:

Didn't work for me. Context-menu for materials are as slow as ever for models with lots of geometry.
What I've found is that the context menu gets slower the more entities have materials applied to them.

Maybe we're talking about different issues?

Sorry for the confusion, the issue I was addressing was the original problem of not being able to right click on materials in large models and delete them because the context menu only briefly flashes by then closes. This is a big problem for everyone it seems, but i swear that changing the windows 7 style appearance worked for me, even in my largest models with tonnes of warehouse junk. It still takes a few seconds for the context menu to show up but in windows 'basic' mode, it doesn't disappear! I think its something to do with the visual style applied to the sketchup windows and toolbar's because if you notice when you right click on them, it causes all your task windows to flash, which if you ask me, is whats closing the context menu. I lost track of who is even having the problem but maybe try different windows appearance options because you will love how smaller your files will be! don't know anything about the greyed out problem, never had that.

I did not realize cleanup3 was your plugin. I cannot live without it! Thank you so much. I was wrong, un-checking doesn't delete the lines. My mistake. I think i was being dramatic to make a point. Cheers!

Let me know if that works for you. Works great for me, and hopefully you will feel as liberated as I did!

One other thing that can help with materials you cant purge which is a work-around I discovered for the above issue....usually the inability to delete materials is caused when materials get assigned to lines that make up your solids, that have different materials assigned to the faces, thus why you cant visually see the offensive material because its on a black line.

If you download and use the free cleanup script called "cleanup3 (to the 3rd power)" you can select suspicious groups or solids and use the checkbox that removes materials from edges. Be careful not to run the script on plain linework as it will delete what it thinks are stray edges whether you check that box or not.

Cheers

Hopefully you've already figured this out, but I finally realized what was causing the right click on materials problem after pulling my hair out over this for ages. Change your Windows appearance setting from the fancy Aero to 'Basic' or the old windows style of visual theme while your using sketchup. Works a charm in windows 7!