I did have some good luck with vinegar last year and will try that again when the plants start to produce. Soaked some old socks every few days. No one had mentioned vinegar, but accidently noticed on the bottle: "protect garden from unwanted pests... soak rags every 7 to 10 days" on the back of a Kroger bottle. I think it did work. I assume if it rains, soak the rags more often. Not sure, but maybe the vinegar smells close to predator urine to a squirrel, or just unpleasant?
Building a cage around the plants is probably the only sure fire thing to do, but I went to do that at Home Depot last year and it started to get kinda expensive to do it right. Last year, I did get quite a decent crop of tomatoes; but the year before literally 2-3 puny tomatoes and then gave up as the squirrels ruined all the rest. Ended up uprooting the plants... Hopefully, vinegar will deter them this year at least so I get some fresh tomatoes. Nothing better than fresh tomatoes. The ones in store here are so bland, but garden ones full of flavor.