McMaster/Carr P/N2414T44 looks like it might fit the bill. However it's 4" wide, not 3". It does not have fabric reinforcing. Anyone know what the durometer should be? This stuff is rated medium.
With fabric reinforcing 3625K12 might work. However it is rated as 70 durometer, which they call hard, so might not be pliable enough.
The other web link is for Neoprene, which is only rated for 200F to 250F. The McMaster/Carr material mentioned above is rated to 500F.
I have purchased silicone products from this company before for various projects, very high quality stuff. You may have to call them if you want it cut in 3” strips, however it’s not difficult to cut with a sharp blade and a straight edge.