I have no bathtub so I do believe this topic has come up a time or 2 because I have a walk in shower
I did post this & since have learned to take the herbs , salts, what have you & mix them in a large pot before I take the shower then after I cleanse myself, I use a cup to pour the mixtures over me or use the salts to cleanse my skin or both. I have herbs that I hang in the shower & have made DIY shower tabs.
I listen to my “Witchy” Playlists that I have on Spotify or YouTube. I usually use YouTube for Celtic meditation music or I play Woke Nation cleansing music. Depending on other things I may have done or I am doing, I will also listen to my Brighid or the Morrigan playlists
I use incense along with lit candles & do a cleanse with soaps that have crystals in them for different intents. I use Lavender & Oatmeal body wash.
There are a lot of ways to incorporate rituals, spells, magic with a shower & not a bath tub
I hope this helps!