An unassuming lead flask, just large enough for a single gulp.
The lead flask radiates a strong Illusion aura. It can be used to replicate the effect of any “potion” as crafted by 5th level caster(Arcane or Divine). To use the drinker only need fill it with any beverage of his/her choice, and give it a brisk shake while strongly believing in the effect they wish to occur.
There is a 5 out of 6 chance the effect they believed would happen does occur, otherwise they drinker just BELIEVES the effect happened.