Edge wrote:

I have a Craftsman 19.2 volt drill with a half inch chuck. Many times,
especially while pressing hard into the material being drilled, the
bit slips. No matter how much I tighten the chuck, the bit continues
to slip. Other than replacing the chuck, which isn't worth it, what
can be done? Is there a spray of some sort or something else to
provide a better grip on the bit.

At least some keyless chucks, including those in Ryobis (your drill
may actually be one) have a ridge in each jaw to grip bits better, but
I know people who still experience slippage problems with them.

As others have suggested, buy hex-shaft drill bits. But even the
cheapest keyed chuck will grip better than your keyless chuck.