I understand a shower can bedeved be used as a mikvah for men what about a bath of water even though you can’t dip but putting your body in and out will it work and if yes is it better than using a shower .
A shower can be used as a mikvah for a man that is a ba’al keri (had a seminal emission) if it is difficult for him to go to a real mikvah. It works by pouring about 18 liters of water (according to R’ C. Naeh) over his body with one continuous flow. He should stand with his hands on his chest without pressing too hard so that the water can also reach his chest. The water has to pour over to him to reach his whole body, Therefore if the shower head is on top of him, that is fine.
A bath will not work for this. Firstly it will have to contain the amount of water needed for a kosher mikvah (40 seah) which is larger than the average bathtub. Even if you have a large jacuzzi size gathtub, still the bathtub is a kli, and it has a hole in it, therefore it is highly doubtful that it will be considered a mikvah even for this.
M”B siman 88-4, Be’er Moshe 6- 74, Shevet Halevi 1-24.