What platform do you play on? PC players using the unofficial patches will probably not be able to get it to work, as it relies on "Restoration looping" (i.e., using one Restoration potion to augment a second Restoration potion). This is an exploit that the unofficial patches have fixed.
If you're not on PC (or if you're just not using the unofficial patches) then I'm not sure. The only thing I can think of is that you're not following the instructions correctly. Also be aware that, while we said the trick can work with other items besides the Locket of St. Jiub, this particular combination of potions does require you to be using an item with +50 Fortify Stamina -- no more, no less. So if you're trying to do it with an item other than the locket, make sure it has +50 Stamina.
It also may not work if you've got any other items/effects that modify Stamina -- this could include enchantments, blessings, diseases, level-up attribute allocation, etc. Check your "Active Effects" tab in the Magic menu to make sure there are no other effects modifying your character's Stamina.
What platform do you play on? PC players using the unofficial patches will probably not be able to get it to work, as it relies on "Restoration looping" (i.e., using one Restoration potion to augment a second Restoration potion). This is an exploit that the unofficial patches have fixed.
If you're not on PC (or if you're just not using the unofficial patches) then I'm not sure. The only thing I can think of is that you're not following the instructions correctly. Also be aware that, while we said the trick can work with other items besides the Locket of St. Jiub, this particular combination of potions does require you to be using an item with +50 Fortify Stamina -- no more, no less. So if you're trying to do it with an item other than the locket, make sure it has +50 Stamina.
It also may not work if you've got any other items/effects that modify Stamina -- this could include enchantments, blessings, diseases, level-up attribute allocation, etc. Check your "Active Effects" tab in the Magic menu to make sure there are no other effects modifying your character's Stamina.