I did something similar. I knew anything on my accounts was already in the palantir dataset used by DHS. I wanted to at least remove presence local on my phone, I didn't bring a computer abroad with me.

I went through my history and deleted twitter, x and bluesky (I didn't and still don't read them via their apps). Probably should have deleted any mastadon links that I viewed in case any were not loyal enough.

I deleted stored passwords for all social media. Deleting SMS was tedious, if you donate, they sell you number to every campaign that is considered the "enemy of the people" by the establishment. The best I could do was search for "campaign" and "Trump" and delete the SMS messages out of the Messages app.

Of course my luck was better than I expected. All I did at immigration was point out one of my kids was really tired (he was quite sick on the plane-ride home). The CBP agent said something about "I'll get you out of here soon" and that was true without a single question.

I suppose my toddler makes me look like less of a risk to national security than when I would return from solo overseas travel. I'm not going to get too comfortable though.