Why 10W40? Why not 5W20? Or 5W30? Why not straight 30 weight? Chains don't care about starting in cold weather. Etc.
Any lubricant is better than no lube for a chain.
Just don't use melted paraffin unless you understand that it's important to avoid catching it and your house on fire.
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Bacchetta Giro A20, RANS V-Rex, RANS Screamer