I've tried a lot of products over the years and I always like good old R13 best. You don't need make this harder than it needs to be. There are a myriad of insulating products that will do the job. But there are also plenty of materials that don't work well at all. So keep it simple.I was sent a product to evaluate that was shaped like an egg carton and it was of absolutely no use at all. It is too thin to work well and is only marginally porous. What we want is a very porous material and it must be spaced out from cabinet panels to perform well. Applying paper-thin materials like felt or pulp does absolutely nothing at all. One could "hang" such a product two or three inches from the cabinet boundary surface and it might provide some attenuation when used this way, but I find no reason to go to this trouble when R13 is more porous, performs better and is easier to use.