I'm using a vintage velo's (woolistic) jersey. I've been getting it soaked under the tap before I head out for a hot ride. I'm not sure how that affects the jersey but it certainly keeps me cooler. I figure wool can't be too bad if it was the standard before all of the synthetics came along.
My wife uses this method when she can't stand my jerseys anymore.
I am a big believer in the "hand wash/throw it in the sink with Ivory Snow" method.
Here's a link that folks may find helpful.
Also, my wife has a Road Holland jersey I bought for her a few years ago.
She says they are more comfy than her regular tri clothes.
Likes them as they are cut for women and she doesn't have to settle for a guy's jersey.
You can machine wash them, but hand washing is easy enough.
Because of the wicking property, you'll be amazed at how infrequently you can wash them. I wash my synthetic jerseys after almost every time I wear them.