I have had people dump cement in my plants too and I want to kill them! They survive if you can clean them in time but the effect is worst on the roots. I can't say for sure which rhipsalis you have there, they mostly look very similar and light levels influence the growth strongly
Since I pay little attention to this Ripsalis.@nikv It's good that I saw it quickly, I could find cement on Ripsalis in a week!
In Cyprus, there are a lot of stupid Cypriots in general!