In the sefer Oleyhu Lo Yibol it is said that Reb Shlomo Zalman Oirbach showered before and after the Mikvah,
When asked why he said.
“I shower before the Mikva because of the Mitzva of VeOhavto LeReyacha Komocho.
I shower after the mikva because of others that are not carefull in the mitzva of VeOhavto LeReyacha Komocho.”