I'd read/heard that previously & when I got my Vernase (excuse spelling) TT from ebay (best shop in the world) I poured boling water in a cup & then put the TT in, for about a minute prodding it about, then tipped the water out & as soon as was humanly possible (bearing in mind the heat) wrapped it over my thumb, tried to mold it into shape, found it bearly moved, & then ran it under the cold tap.
So for me it made no difference,

but it sure can't hurt to try. Have fun.