Cut the end off one of these and you have the same thing that can stand up to the heat
I used the black "sleeve" that came in this kit that is 3/8" ID
https://www.amazon.com/gp/product/B00XYDFW8K
I had to disassemble the hot end completely, then slide it over, then cut the hole for the heat break and nozzle, then reassemble. Trying to cut a slit and slide it over didn't work very well.
There are vacuum caps that can go over the vacuum tip https://www.amazon.com/High-Temp-Silicone-Rubber-Protective/dp/B00XYDFW8K/ref=mp_s_a_1_18?keywords=vacuum+cap&qid=1668014726&sr=8-18