Let's face it, when it comes to traction a lot depends on your grades ( I have a 3.4% ruling grade) and the lenght of trains you are attempting to drag up hill.
I've been expermenting with various types of products, including the snot. Currently, I'm back to traction tires but I'm still looking for that "holy grail" of O-Gauge traction.
Bull Frog snot - I had good success with it at first, but after a few weeks engine traction actually got worse than with plain rubber tires. Seemed to me the snot became imprenated with track oils/dirt. At first, installing the snot wasn't as easy as shown in the video's because of the tire grooves. I did come up with a fix for that.
I took a small piece of plastic sheet and filed one edge to match the profile of a drive wheel without the t-tire groove. Simply apply the snot per the video and then immediately place the tool against the wheel while it's still turning to remove the excess. This will completely fill the groove quickly & easily leaving a perfect snot tire.
I'm considering adding a small amount of fine sand to the snot to see if that aids traction. I haven't tried that yet. Not too sure running sand on the rails is a good idea.
I have tried regular silicone with disappointing results. Works ok for a week and then it falls apart. I alos tried a "sanded silicone" product found in the tile section at Lowe's. It dried hard as a rock and made a for very rough ride. It's heck to get back off too.
Currently, I'm applying a drop of black paint to the wheel groove and then reinstalling the traction tires. The paint seems to help the tires adhear to the wheels better and isn't as difficult to remove as CA glue.
For now, either double heading or doubling the hill appears to be the answer.