+1 for the copper manifold. The silicone will just collapse. I used to use a SS braid but switched that out as well because I was leaving too much wort in the MT. I designed a square manifold that fits snug into a round cooler. I did not solder any joints and it slips right onto the nipple of the ball valve with a slight "snap" into place. When done mashing I can remove it easily, take it apart and clean it out and it almost completely drains my tun.
Nothing Left to do but smile and drink beer.....
The Commune Brewing Company-Perfecting the "art" of beer since 2010