Water hammer - arrestor hasn't fixed the issue

Hey all, I've owned for ~3 years and had bad water hammer when the dishwasher and washer run - like it is a big thump and almost shakes the house. I'm in a townhome built in 1973.

I had a water pressure arrestor installed on our main water line about a year ago in the hope it would fix the issue, but it really didn't. The water pressure was definitely too high prior to that, but we have it set to about 58-60 now and those appliances still hammer like crazy. I kind of gave up for a while and moved on to other things, but I'm not worried about it again :)

What else could even be done about it if the arrestor didn't work, and any idea what it'd cost for a plumber? I'm in Northern VA. Just looking for any idea before I start contacting plumbers, any tidbit of advice helps.