To remove all effects at once you simply need to highlight all the clips, at the top of the inspector you will see that its inspecting whatever number of clips you highlighted. Then you can remove the effects and corrections.
"Always look on the bright side of life" - Monty Python
I tried this but it doesn't work... I selected 3 clips which contained the same effects, but removing an effect just removed it on a single clip not all 3 ! Is it just me ?
I'm using multi cam clips. Just mentioning it because I've noticed that FCPX often behaves differently with multiclips.
Yes, it is indicating that multiple clips are selected.
Well, I just tried it again and couldn't reproduce the issue this time. It now works as expected. Effects get deleted on all selected clips. Very strange ! I'm either going crazy or they are sometimes strange things going on with multi clips ... Thanks for your answer anyway.