Ok, point taken. But I just don't think that he would risk blowing the plan by going there himself, and as you correctly pointed out, taking the chance of being recognized.

It's funny how we all interpret things differently when watching the same scenes.

I always assumed that Clemenza had someone plant the gun because of Sonny saying "Hey, listen, I want somebody good -- and I mean very good -- to plant that gun. I don't want my brother coming out of that toilet with just his dick in his hands, alright?" and Clemenza replying "The gun'll be there."