You can get bulk ECN2 chemicals that meet specifications. Probably cheaper per lot than with weak kitchen chemicals.
The problem with "manual" removal of Remjet is that it ruins the emulsion … with your latent image! All DIY advice and Youtube videos lead to a ruined movie. If the method you use recycles the laundry and does not filter out the washed-off Remjet particles or does not protect the emulsion side of the film during the process, Remjet particles will be embedded in your film.
Kodak's ECN2 processing manuals (still available) state that approximately 30 psi of water are required to satisfactorily remove the halogen backing. However, you cannot use 30 psi on the emulsion side without risking damage. Even commercial ECN2 processor machines ruin frames here and there. Regardless of the method you imagine, either low pressure water or cool air must protect the emulsion side of the film.