I myself use Full Synthetic motor oil, and it seems to work well, as I have basically not noticed any difference to expensive chain lubricants....
The oil is expensive if you are buying and using liters of the stuff, but due to the small amounts needed for a chain, it still works out cheap!
I have been using Full Synthetic in my car engines since the later 80's, and a lot of progress has been made with it, I have been very happy with it in all my engines, in about 8 cars, both private and company.
So as the oil suffers extremes of heat and pressure in engines, quite happily, a bike chain is really no problem for it!
I use Long Life 3 usually. There is a later version, often needed by BMW Engines, but I have myself never used it.....
VW Diesel Engines, which "decide" when the oil needs changing, with my driving style allow around 30,000KMs, between oil changes, which works out cheaper than using mineral oils!
But each to his own!
Some friends of mine buy really expensive chain lubricant, as if it did not cost a lot, they would never buy it, and some even "brag" about how good their lube is......because its expensive!
Regards to all
Andy
PS. I have never used the Aldi grease myself, so I do not have a clue as to how good or bad it really is, sorry!