I will say this: as an experiment, I started blooming only one soap, my Mike's Naturals Orange Cedarwood and Black pepper. It did make the soap a tad easier to load.....but after a month or so, I noticed it started losing its scent.
Curious, I took the entire soap's contents out of the tin, and noticed the bottom of the soap was turning a pinkish-dark brown and had a musty smell to it! I tore away the part that was discolored (about half the soap) and put it in another container, and I used the rest of it. I just got a replacement Mike's naturals in the mail yesterday and noticed the new soap had a much more robust scent. So I'm not sure I would recommend blooming.
I'm curious what other member's discussions on this are, though.
I don't bother. I started off blooming the soap, but often would forget. I didn't find enough of a difference so I stopped. I can get a decent lather as long as the brush loads well.
You may not want to try this with some of the croaps (very soft soaps that have a texture more like thick creams) as you'll get too much soap on your brush.
I bloom all my soaps. I like to apply the bloom water to my face and leave it there while I brush my teeth. I then load and lather on top of it. I treat this as my pre-shave.
I'll try it on occasion as a last ditch effort to get a decent lather from an older dried out hard soap or a very poor performer but it's not something that should be done by default as it just ends up helping you wastefully dump soap down the drain. I'd rather not use soaps that need to be bloomed.
I've read several threads where people have stated that a particular soap didn't last long at all. We're talking about soaps that might last a normal person five or six months gone in two to three weeks. Sure enough they are soaking the soap via the blooming method prior to use and dumping all of that soap down the drain.
For example, as an experiment, in the morning a half hour before your shower every day take your bath soap and drop it into a bucket of hot water. When you jump in the shower a half hour later retrieve the soap and use it. As you pick it up and began to lather it you'll certainly get a nice lather as the whole soft outer layer of the soap was used up to provide it. Sure it'll lather easily because you're using ten times the soap that is needed. But see how long a bar lasts when you do this. This is essentially what you are doing when you bloom a soap.
If it's a good quality soap then blooming should be completely unnecessary.
If it's a hard soap and a very soft badger brush, I would drip some room temp water on top to bloom it. I even do this with some soft soaps like Mystic Water if I'm using a soft badger because it will load faster. I rub the bloom water on my face so it's not wasted.
I don't bloom if I'm using a boar brush. Marco's method works like a boss in this case. This is my preferred method for soaps: Marco method plus boar. No blooming.
It's best to experiment and see what works. People who struggle to load or lather some soaps like Williams have had more success after blooming it.
I always bloom, it makes things easier all around. I may "waste" a bit more soap this way but it's worth it to me. I do make sure to let the soap fully dry (about 24 hours) before putting the lid back on to return to storage though.
David from Stone Cottage Shaving recommends that you don't bloom with his soaps. He says you get a much better lather with using a damp brush and adding a bit of water as needed
I wouldn't bloom really soap soaps, the ones bordering on creams. I tend not to bloom my soaps anymore as I haven't noticed a big difference either way. Blooming is more about softening up the soap so that you can load it more easily on the brush. I have found it just takes some extra loading time to get the same loading result as if I had bloomed the soap.