Splicing 24 awg wires - wire and tool selection
You do NOT need the dedicated crimp tool for these splices.  What you need is something that will close with the jaws parallel at the proper gap distance.

A pair of ordinary slip-joint pliers works well when you have the pliers set for the larger gap size.  Add a shim of some sort if the gap is too large when the jaws are parallel.  The smaller slip-joint pliers that I use have a gap that is just about bang-on.  The larger slip-joint pliers are used with a small piece of 1/16" PCB material as a shim.

I actually do own the proper crimp tool for these connectors.  But I rarely use it - the slip-joint pliers are usually close at hand whereas the proper crimp tool is put away in another building.

All that said: you shouldn't use these in a location where they might get wet UNLESS you have the grease-filled version.  Although the grease-filled version is a standard item for telephone repair persons, I suspect that Home Depot doesn't sell them.

What I would do instead is simply twist and solder the conductors, then encase the connections with adhesive-lined heat-shrink tubing.