On a lot of intensive courses say the same thing. Filler words should be ruled out when talking. The same goes for other tricks. I used to be a very very heavy user of 'ehh' when blocking, it sounds better to stutter in all honesty. Stuttering is understandable, but the tricks that come with it aren't. For example some severe stutterers might slap their leg and nod their head violently to get the word out, people don't understand that as a stutter and basically think you're demented. You're definitely on the right track my friend.