The potion of orcish war juice should be at least situationally useful for heroes of any race. One way of doing this is to make it more in line with the portrayal of a similar substance in The Lord Of The Rings: have it give useful short term buffs to anyone (minor healing, cure wounded legs, one point of increased strength) with long-term penalties such as a boatload of abuse. Meanwhile, the potion remains a good thing for orcish characters to drink: they get much more healing, bigger stat boosts, and no long-term penalties (though there may be short-term penalties such as mental stat reductions).