We started using the Wago 734-231 tool that I got from work. We recently started using a Wago connector like the ones used on the Solenoid Breakout and the Analog Breakout so we had a bag of them and will be getting more.
https://eshop.wago.com/JPBC/0_5Start...6E 608DC1C7D0
When I get to our build site later today, I will post some pictures showing how to use it properly since it is not intuitive. Using the tool the most obvious way is no better than digging around with a small screw driver. It was a revelation for us when we were shown how to use it properly.
You use one hand to hold the connector and the tool (opening the jaws in the process) and insert the wire with the other hand. The long shaft will also work for the Wago connector on the +5Vdc connection on the PDB. It will NOT work for the large Wago connectors on each side of the PDB that are for the various 12Vdc power connections.
It is pretty inexpensive ($0.26) but all the companies that I have found selling it have minimum order values of $15-$50 plus shipping in the order of $15. If you find a place to buy them, get a bunch. Last week, our Production staff installed 5 circuit boards, each with about 24 connections and broke 2 of these tools.