Barami hip grip with a Tyler t-grip. Makes inside the waist easy, even with a pair of jogging shorts and a t-shirt.
What he said...but I don't use the Tyler t-grips, just the Barami Hip-Grips. On most of my j-frames and I carry them daily. Usually a 640-1 but occasionally a 442. Either way, you forget they're there. And they don't come loose, as the cylinder is held tightly by your belt or waist-band.
You can buy these for j-frames or k-frames. As you know, the L-framed Smiths have a k-frame-sized grip.
I've used these Barami's for about 40 yrs. I have many; you can buy them for other brands as well as Smith.
And they're cheap...@ $26.00 or so. The pix are reversed image: available for right-hand use only, IIRC. Here's the link:
Barami Hip Grip Concealed Pistol Revolver
Here's the clip that fits on the belt or waistband.

Here's one I use on a L-frame .44 special model 696

It can fit on your belt like this...

or it can fit on your waistband like this

Obviously, with your t-shirt hanging out, it becomes invisible. You can even wear it with the shirt tucked in, just pulled out a bit at the waist to flop over the shirt. You can easily wear a dress-shirt that way; I have often.
Sonnytoo