When I first started using foundation, I stuck with make up brushes. I don't know if it was a technique issue or I had some weird thoughts about applying with sponges. Either way, I avoided sponge applicators until recently.
The important thing with using the wedges is that you should find the non-latex brand because they absorb the water better to give you a better result when applying your foundation.
While my blending technique still needed a bit of work, I was happy with the result and gave up foundation brushes for awhile. I liked the results so much that I wanted to venture into the blender world, but I could not bring myself to spend the money for the Beauty Blender. So I decided to search for its cheaper counterpart.
Sonia Kashuk Blending Sponge and try it myself. There were two sponges to choose from but for the same price of $9.99, I decided to pick up the pink sponge that came with the cleanser. Now, I don't know if there is a difference between the two sponges offered by Sonia Kashuk, but from what I've seen them look the same outside of color.
As far as the cleanser, well it isn't anything impressive. Its has the consistency of soapy water, heavier on the soap side. From the videos I have seen, it doesn't have the gel quality like the cleanser made by Beauty Blender. Honestly, it doesn't do much of anything to clean the sponge.
When I do clean the sponge, I use baby shampoo and warm water, just like I do with my make up brushes. My sponge seems to be permanently stained now, but I can tell if it is clean when there is no more color rinsing out in the sink.
This product is a great buy. You can reuse them (something I never really did with the wedges), they are great at blending, and it is affordable. While I would recommend throwing it away at some point, I plan to put quite a bit of use into my sponge before that happens.