Morning
Not 100% sure on that, but then depending on your total skill points, you will gain on fails from the GGS (pending how close you are to 700/720SP).
http://www.uoguide.com/Publish_16_-_Guaranteed_Gain_System
Using Soulstones, I dropped 4 skills to 0, and took Anim Lore, Taming and Magery (to recall). With an average of 250-300 SP, so I would gain faster. One night I messed up dropping skills, after capping 100 Taming, I dropped it to 0, by mistake. On using the stones, and my jewelry to get to 71.6 taming, I capped back to 100 taming in 1 Saturday (+-8am till 2am the Sunday). It was not pleasant, but I got it out the way. A few days later, I found a 115 taming scroll, did the same thing again, and dropped all my skills to 0, and took about 4h to get 100-115 base taming.
Hope that helps.
Regards
T. Pwent