sealing over rust?

[StumpedCanary]

My bath is corroding badly on each corner and cannot afford yet to replace. Have bought a liquid to bond rust and hopefully put a seal over it to stop it getting worse. The owner before me has used squirty sealant over it (between bath and tiles), am I correct in thinking I ought to somehow remove this before using liquid? Have also bought a strip seal, would this prove a better option than re-sealing with the plastic/rubber squirty stuff? Help please!