While I have no particular training, this does not match my experience or intuition.

I think the best thing to do, when the situation permits, is to clearly think through what you want to say before you start speaking. Then you do not need filler. If you find yourself reaching for filler, then I think it is better to stop entirely until you clearly think of the next cogent thing to say.

(Note thought that filler is different from a transition phrase. A transition phrase, which might include "on the other hand" and similar phrases, don't add meaning per se but do clearly indicate you are shifting arguments slightly which can help others follow your reasoning. But that is meant to transition, not form filler, and even then transition phrases are often overused.)