A friend recently spilled beer on my dry-clean only flat cap. As I was picking up the cap from the dry-cleaner, it occurred to me I should have looked first for a more environmentally-friendly alternative. What such alternatives exist?
Actions like those below are always YMMV / Caveat Emptor / DTTAH (unless you are confident that you an do it intelligently)*
"Dryclean only" probably means that the product may be damaged in some manner by the normal asking process. If you can identify what factors cause damage to occur you may be able to allow for them of to prevent them. Sometimes the manufacturer may be being careful or lazy - by saying "don't wash me" they limit liability and possibility of damage by "cowboys".
For example a product may be crushed irrevocably by tumbling with other products. it may be water soluble or colours may not be water fast or soap or detergent may cause some reaction. There my be a component that cannot tolerate getting water inside it.
Contacting the manufacturer or agent may provide useful guidance.
In many cases this is not possible and you will have to decide for yourself.
In the case of your cap it seems likely that mechanical damage may be the issue. Or it may contain cardboard or similar stiffeners which will be permanently affected by water soaking. If a careful examination suggests that water by itself will (probably) not cause damage you could insert a cloth "stuffing"to main tain its shape and sponge it with a well moistened sponge. Plain soap is unlikely to cause problems and you can probably rinse it out while still towel filled.
Dry cleaning usually uses solvents applied against a surface to cause contaminants to wick out of the fabric. If you know what the contaminant is then yo can choose a suitably low impact solvent. In the case of beer, it is likely that "drycleaning" with water would work as well as most other things. ie a semi soaked towel or sponge applied to the surface while the hat is kept in shape - repeat as required.
YMMV - Your mileage may vary.
Caveat Emptor - Buyer beware = It's your responsibility
DTTAH - Don't try this at home (unless ...)
Since the comment mentions wool, the single best way to care for wool is to spot-clean by hand. You shouldn't need to routinely dry clean wool and hand washing spots out is perfectly reasonable. The big problem is that when wool is tumble dried, bad things happen so if it is bad enough you can always run it through the wool cycle and then hang up to try.
I see the mechanical washing as a bit of a last resort with wool though because I have had woolen articles of clothing damaged by washing machines. I much prefer to hand wash trouble spots.
"Green Earth Cleaning" claims to have a green dry cleaning process that is completely safe.
However, they also seem to be a bit confused by silicon and silicone, stating "GreenEarth cleans with pure liquid silicone. In essence, liquefied sand."
My understanding is that even though silicone contains silicon, it's vastly different. It may still be much better than the traditional perchloroethylene though. The chemical name for the solvent is decamethylcyclopentasiloxane, according the Wikipedia article linked below.
Wikipedia lists some other alternatives, including liquid CO2.