How to do it:
1. With the scroll you wish to use in your inventory, select the scroll spell from your magical inventory as you would normally.
2. Open any container and put the scroll into it (i.e. baskets and chests) *note that you cannot place items into plants, and that the scroll must be placed into a container! Doing so will keep the magic of the scroll selected as your current spell. If you drop the scroll, the spell will be removed.
3. Cast the spell - it will work as though you had the scroll in your inventory, but will not cause the scroll to disappear.
4. Retrieve your scroll - it will be intact in the container that you left it, and the process can be repeated.
User Tips and Notes:
I generally use corpses, as they are convenient containers and appear exactly when you are likely to need a scroll of vitality - right after a fight. I have even played characters which function thematically as necromancers in that there magical abilities require corpses to use. Aside from using healing scrolls to cut down on potion use, I primarily use two other scrolls with this ability. The first is the scroll of Ekash's lock splitter. Scrolls that unlock high level locks are very valuable to anyone who steals as much as I do, and I hate to see such a nice scroll vanish after one use. The second scroll that I use is easily the one that I use the most and it is the scroll of windwalker. Although there are some characters that I intentionally play with or without using the scroll glitch, using the windwalker in this way is highly convenient for travel - just follow the four steps above, fly off into the distance, kill a cliff racer when your spell is almost over, and repeat the process with its corpse. I like this method because it's a clever way that I discovered to navigate the vast world in Morrowind, I don't need to worry about which areas have both a silt strider and a boat for transportation transfers transfers, and it's not the same as just typing in a console command (you still have to obtain the powerful scrolls after all and have the right conditions for the glitch, the only difference is that the scrolls aren't destroyed after use). There are doubtless tons of ways to use this glitch, especially as you can enchant your own scrolls in Morrowind, so I hope you found this post informative and have fun testing this out!