Am I trying to roll an impossible flask?

I know I used Seething life flasks of warding but ended up rerolling them.

Reason : you only remove the curse but get no curse immunity because the instant flask has no duration. When a necromancer cursed you, you pop the flask and he instantly curses you again, so vs cursing mobs the flask mod is totally wasted.

I guess thats why you don´t find any for sale, Warding suffix is best used on a non-seething flask. The mod combination, however, exists ;)