Maybe, maybe, that DuPont Teflon spray would be good for a chain on a bike. If you were careful, and sprayed between the links. A regular silicone would not hold up well under your somewhat aquatic conditions over there on your side of the pond, unless you were able to apply it after each ride or so. The Teflon may be an exception as it leaves a coating on the plates and pivots. WD-40 would do the same, only it dries to a sort of varnish, and washes away easily. But WD-40 is used to disperse water, not lubricate, essentially.So an oil, with some tenacity, like a bar and chain oil, or a specially formulated chain oil, is going to have the stickiness, or tenacity, to stay where it's put, and do the job. Used in conjunction with the Mickle Method.