Cork has been around a long time, and it is pretty clear at this point how to take care of it. Foam on the other hand, has recently become very popular....dare I say it's the 'in' thing. Regardless, if you have an EVA handled rod or even a proprietary foam like Daiwa's 'Air Foam'....ensuring longevity is the same. Upon purchase of your rod (or after a cleaning if you've fished with it), comes the protective layer. This layer will not only protect your foam, but make it much easier to clean. Just purchase a quality leather water and stain repellent. Purchasing a leather protectant ensures no solvents or damaging propellants. If it's gentle enough for leather....it's a safe bet for foam. Here are some examples...

Untreated Daiwa 'Air Foam' grip...

Treated Grip. Notice the grip is visibly moisturized and protected...

I like the reel magic aerosol for upkeep. After an outing,  use a damp microfiber towel to gentle wipe down my entire rod, finishing with the handle (this will dirty up your towel). After the foam is clean and dried a while...mist it with silicone. The aerosol reel magic is quite a different product than the non-aerosol....the aerosol leaves a thin layer of active ingredient whereas the pump spray is 100% active ingredient and would leave your handle oily.

Great tip thanks