What I have done to some of my bowls is to make a holder for the bowls.
It is really simple and works great!
#1 get a small bag of tile grout from any hardware store.
#2 mix up some grout place the pile of wet mixed grout on a peice of seran wrap on wood or a work bench.
#3 cover the pile of wet grout with seran wrap or thin plastic, then place your bowl ontop and squeeze the bowl into the tile grout, forming the bowl holder in any desired shape.
#4 when the grout is almost dry, in a couple of hours remove the bowl and top layer of plastic or seran wrap.
$5 let id dry for at least one full day after you made your bowl mold, you can even seal it or leave it as is. when it is completely dry you simply place your bowl back into the hole made from the bowl.
It will not tip over, and the grout makes a good scratching post or shedding post.
I would attach a photo but I did not take a picture of mine yet so...
Use your imagination.
hope that helped.
Nick Gancarz
Boa's Ark c.b.r.
ps I should probably patent the idea....