It's likely to be better than doing nothing, as is using a HMP ptfe rich compound or similar. As you say, some is bound to make its way into the fibre washer housing (there IS still a bushing bearing of sorts between the washer and where the spindle is exposed within the pipe). Trick is to FIRSTLY spray a little acf50 into the spindle ends and turn the ignition on and off a few times to ensure that it works around the bushing bearing surfaces removing some of any corrosion or gumming up present before applying the grease.
Smear enough grease and try and work it around the spindle ends as hard as possible and some is bound to reach into the bushings on either side where the anti-seize properties of the grease can do its thing. Repeat as often as you feel you need to given, say, 500 mile initial inspection, and the elbow grease becomes part of the known regular cost of ownership. A tin of grease costing 30 Euros (I ordered some today) delivered is going to likely last the life of the bike so it all boils down to whether owners can be bothered. There's £1500-worth of motivating argument to being bothered.
To those arguing it all should be on BMW...perhaps but it is what it is. Did owners of Matchless G80's back in the day bemoan the awful worm drive oil pump which used to wear out almost as fast as the tyres? Nope, they replaced it as and when needed. It was a cost of ownership even if it was a design flaw. Did owners in later years of RSVs and RSVRs bemoan and hold dealers ransom over failing clutch slave cylinders and ignition coils? Nope, they upgraded them at their own cost as they were known design faults. Point is, all these were/are fantastic bikes in their day and nothing in this world is perfect....not even Honda car engines it seems...
....lets look at that shall we? Honda's latest super efficient high torque 1.5 direct injection petrol turbo has been the subject of countless complaints in the USA for a few years due to gasoline dilution of the sump and engine oil. Those same engines are now in the UK and fitted to all Honda's new line-up of civics and CRV cars. Honda's answer wasn't to issue a world-wide recall but to convince buyers that the cost of ownership is 6K miles engine oil changes to avoid engines going "bang" within their first few years of life. They've investigated the issue, known from the outset by their designers it seems and now spell out oil changes have to be this regular within owners' handbooks. It seems many people ignored this and their engines let go as a result. These were the same people who argued that it was a design flaw and that Honda should be taken to the cleaners. The truth, just like BMW's case, is that they designed the engines for fewer emissions to comply with USA and EU environmental legislation, and those that know their engines also understand that direct injection petrol engines, when cold, saturate the bore in gasoline which seeps past the rings and mixes with oil. All oils are designed with some degree of gasoline dilution in mind, but in the case of direct injection engines, miles between oil changes should be halved compared with conventional injection.
In BMW's case, noise regulations lead to a silly situation where they either strangle the crap out of the motor or add a simple valve. They chose to do the latter and good on them. The cost of ownership is therefore owners getting their hands dirty. If the greasing makes no difference at all, then I would take the view that the design is not fit for purpose, but if it proves to be the answer, this will become a non-issue and melt away for everyone except those with an aversion to spanners. You have to question whether responsible ownership means that owners shouldn't be expected to roll their sleeves up though...