Hi. You need to think what caused the rot. One of the commonest causes in cultivation is too low temperature , not enough light. What I would do is cut away ALL the dead tissue with a sterile knife, wash the whole plant in a mild chlorine solution - don't forget to rinse off the chlorine with sterile or boiled water - then leave the wounds to dry for 24 hours. I wouldn't treat them with anything. Get a large jamjar or similar, quarter fill it with fine gravel and add a couple of tablespoons of water, not enough to reach the top of the gravel. Sterilize the whole by microwaving for about 3 minutes. Don't let the water boil away. When it has cooled, pop your plant into the jar (its ICU)and seal the lid.It should fog up. Make sure it is not in contact with any base water. Some people use sphagnum moss, but unless there are live roots, there's not a lot of point. Keep it very warm but out of direct sunlight. In a couple of months ( if you are lucky - your plant is critically ill) you will see new roots forming.

I'll just add my two cents from my failed grafting experiment. I had a mystery bonus cutting that was clearly not going to root, plus a generic rooted cutting (root stock) to experiment with: I compared widths of both: and they looked pretty comparable. You can see on the left where the base is sunburned and getting squishy. These were my tools and the tip or scion: I put the two side by side and sliced at 45 degrees across and the match-up was pretty good: but, alas, the scion didn't seem destined to live. It just kept shriveling further and further up the tip and the union never took. On the plus side, the base sprouted no fewer than six new shoots and continues to thrive.

Powderpuff, I just started buying plumeria plants in the last summer of 2011. I was looking trying to find the perfect soil to grow my plumeria I called the president of the Plumeria Society in Corpus Christi Tx, who was also the president of the Botantical Gardens in Corpus, and asked him what they use. They have the most beautiful display of Plumeira plants there you could ever imagine. He said they use Miracle Grow garden soil, commercial perlite, and alittle cow manure, to make their soil. Then I saw K's soil he makes. I went with K's mix, he had simple instructions, that were easy to follow, but I added a bag of compose cow manure to his mix. My plants grew like weeds. Then in the spring, I found the information on how to make gritty mix. I could never find the chicken grit, I used turface in its place. I have to say, all the cuttings I put in it in the spring rooted, I was impressed. I potted up my newly rooted cuttings in this gritty mix and put them in the yard in 5 gallon plastic pots next to the back fence, that get almost all day full sun. I was not worried because I have a sprinkler system that comes on every other day. I came back the next week and they were all shriveled up. They all died, just like everyone did on the green mile. I lost all those new plants. If you are able to water you plants every other day, and in the summer water every day, the gritty mix is great for growing plumeria and desert roses. In Texas we have weeks of temps over 100 degrees. Some of on this forum, get together and meet to discuss plumeria, they had similar experiences trying to grow plumeria in the gritty mix. I love the gritty mix for rooting, but not for growing my plants. I am sticking with what works for me in Texas. I have renamed K's soil and now refer to it as " Special K" soil . and Barbra

Should i have left it alone to begin with? I tried to, but i was watching it get more and more rotten by the minute and became convinced it was rot because of the clear yellowish liquid that came out when i poked the soft part with a needle. I have grown many non rooted cuttings and never experienced any rot or growth issues before. I will definitely leave it now, thank you for your input.