Ichor of illumination and Ichor of rage can be used slightly after being refunded
I saw someone do this in game and I tried it out myself. I haven't tried it in custom games but in the normal blind pick it works.
Basically what happens is when you refund a potion purchase there is a very short window to use the item even though it is refunded.
It can be done by purchasing a potion, then refunding, hitting escape, and using the potion from your inventory rapidly. (I have not tried clicking the potion to use it, just the quick cast way by hitting a number)
- buy ichor of illumination or rage
- rapidly after refunding the item hit escape and then whatever keybinding you had to use the item.
- retain buff from potion without paying for it