They have foil over the bottle opening now?!.. That's a good thing and I can see where it'd help keep the stuff from drying up in the container.
The old trick was to put marbles in the bottle to boost the liquid level up to the top,,keeping the air out.
All that did was leave me with a petrified bottle of Tru-oil with some beautiful old cats-eye marbles suspended in it.
I think it's still around here somewhere buried on a shelf!
The stuff would tack up but never completely dry on the wood. Always remaining a bit soft and gummy, never a real honest to goodness hard finish.
I tried waiting days and even weeks to dry, micro thin coatings, drying boxes,,,,time to move on.
I've used a lot of different things for finishes over the years. I do a lot of restoration,so simple shellac, usually orange is used often.I mix my own from flakes.
For a varnish finish I prefer a tung-oil based varnish. A plain off the shelf product from a HomeDepot type store is all. They are usually well thinned and sold as wiping varnishes. That's OK too as they work very well to use as a sanding medium to fill the pores of the wood if needed. No extra thinning needed.
It actually does dry and rather quickly, usually 24hrs is enough. It dries hard and is never gummy or tacky like some linseed concoctions.
It can be colored or toned to match older finished easily and gives a great 'in the wood' finish look when you desire just that. Can be built up too.
As a top coat over the last sanding and rub out w/pumice or rottenstone I use a commercial artists Rapid Dry Oil Medium (Martin Weber is the mfg name on the small bottle).
A couple drops of it mixed w/a couple drops of linseed oil dotted around the stock and rubbed to a micro thin layer and left to dry. It will dry hard because of the 'medium' but not glossy. Just a nice glow to it. Water proof too and won't water spot unlike plain linseed.
I stain just about every piece of wood I work on. I usually use an alcohol stain the first coat. Then follow up with oil based stains over that. Sometimes several different shades. I reapply oil based stain lightly in between sanding the coats of finish too no matter what finish I may be using. Surprising how much you can enhance the color and tone by these inbetween the finish coats stainings. Make sure you let them dry completely before continuing the finishing process.
Well that's what I do,,doesn't make it the right way or only way by any stretch of course. It just works for me.
Results are what matter.
If T/Oil works for you, then no need to turn away from it.
I just wonder how people do it when I see some of the nice finishes done with the stuff.