When you stir it up, are you using the brush? I sometimes find the brush will not dig deep enough, to mix everything, so I use a small screwdriver to mix it, for me, this seems to work really well.
You may want to try using a small acid brush instead of a tooth brush. This makes it a little easier to paint the paste on the splines, without having it all over the place.
You only want to paint the surface, not fill the splines up. If you put too much on, it will just force it out of the splines and pack it up against the inner dust seal, and throw it around the black ring on the inside of the pumpkin making a mess.
Thanks for replying, let us know what you find when you report back.
Ride safe.