[Cob] Another inquiry on sealants...

[Benjamin Brownell]

I've done some searching and reading and testing on this question, but thought I would still check in here for new insights or advice. I feel like there must be alternatives to the two standard answers on weather-protecting earthen structures-- 
a) just cover it already with proper roofing, or b) give it a natural finish (oil, lime, etc) but watch closely and plan for upkeep

I'm curious if people have had success with other treatments, even 'industrial' versions, that could allow for durable application in public settings without utterly sacrificing the aesthetic qualities of the substrate. I believe rammed earth buildings are often sealed with versions of silane/siloxane that is a semi-breathable treatment often used on concrete, but have not tried it (nor know of a tested version for natural plasters). I have seen cob partially painted with latex to some good effect. There are a multitude of other more and less frightening compounds available. Perhaps this is heresy to purists, but I'd like some alternatives to get mainly sculptural demonstration works into the public eye and not watch them fall apart with the slightest neglect/overuse. Not so concerned about breathability in this case, although I think different treatments for different exposure levels could be combined for maximum benefit/minimum impact.
Any info, speculation, anecdote is welcome!