All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
In performing Ghusl (ritual bath), one must make water reach all external parts of his body, he must make water reach his scalp and make sure that the water has reached the places which it may not reach. Ibn Qudaamah said: “If he washes once and the water reaches all of his head and body, and he did not perform ablution, then this is sufficient for him, after rinsing his mouth and sniffing water into his nostrils, while intending Ghusl and ablution, although he has left what is optional [i.e. the perfect manner of performing Ghusl]: what we have stated here is the manner of sufficient Ghusl.” [End quote]
Therefore, it is not a condition for the validity of Ghusl to wash the right side and left side three times but one has to pour water all over his body whether or not this is achieved by doing so three times, but it is disliked to pour water more than what is needed, as this is wastefulness which is forbidden. An-Nawawi said in his explanation of Saheeh Muslim: “The scholars agreed that it is forbidden to be wasteful in using water even if one is on the sea shore.”
For more benefit, please refer to Fatwa 81405.
Allah Knows best.