So I just had my first Lush purchase a few days ago. I am beginning to love the scents and everything! I just wish I understood each product a bit better, including: bath bombs, bubble bars, bath melts, etc. Can someone please explain the uses and how you would use them? Do you suggest that I drop the entire bath bomb for one use or cut it up? And what about the bubble bars? And how long do lush products last before they lose their effect. (By that I mean, let's say I bought a bath bomb a few days ago and I would like to store it up to use it for a special occasion. Can I do that or do I have to use it those few days that I bought it? Thanks.