its hard to clean the leaves. but its probably good at the early stages of the plant way before harvest time.
from what i read about flea beetles (a big problem here) is that they overwinter as adults in garden debris and at the edges of the woods.when the temps are in the 50's or more on a consistent basis they become active.
row covers work well if they cover without any holes or places for the beetles to get in. i've done this with eggplant. spinosad is supposed to help but it didn't for me.

I didn't realize that it was the adults overwintering. Maybe a really good row cover can help. How about the Surround - is it a good product to use?

They ate all my bok choy, too. I read that they like weather that is hot and dry. When spring turns to a hot and dry summer, they go wild and eat everything. I haven't tried it yet, but a moisture-retaining mulch might help.

if i were transplanting flea beetle susceptible plants i would put surround on them. but when there is new growth the surround would have to be applied again. the problem with that is if some of those leaves are your product you will be spending a bit of time washing the surround off. it doesn't just come off like dirt.

What I have done with 100% success is a combination of row covers and sticky traps made from vessels like 16 oz water or pop bottles filed with water, capped and than covered with tangle Foot. Place a bottle every 3' to 4' in the row and within 18 hours you should be FB free.

This work because the bottles warm up during the day and than at night when the air temp drops the FB jump on the traps seeking warmth and stick. You will sometimes get a good guy or two as well.

It's really hard to wash all the Surround off of crops so it looks like your leaves are covered with pesticide residue to the Organic buying public.

Good advice! I'll definitely try the sticky traps.