when I put things in the dishwasher I worry about it being akin to sandblasting - mindmapper am I being pedantic? (Usually if I am in doubt anyway, I just handwash)
I don't know what kind of bicarb soda you have in OZ but the stuff we have here in the US is certainly not "abrasive" per se., and does not have a Mohs hardness to affect stainless steel (SS is 5.5 to 6.0, soda is 2.5) and I know from personal experience that it will not damage chrome plating because I have used it for many years to polish my vintage chromed appliances. If used fairly dry, it will abrade many plastics but so will a fingernail. In a semi-liquid slurry it will not.When I was still doing engraving in glass and gemstone carving, I often used bicarb in a tumbler to clean carved amber (same hardness as bicarb), and the plexiglass (3.5 on Mohs scale) mounts in which I displayed the engraved glass panels. Dental laboratories use it to polish false teeth AFTER the use of abrasives. Regular tooth paste IS abrasive (calcium phosphate 4.5 to 5.0 on Mohs scale.)BiCarb does abrade polycarbonate much harder than plexiglass (which is an acrylic) very easily and as you have pointed out is a polish, is used commercially as a polish and will if used enough wear the material, as will egg shells spun at high speed for over an hour.It is best not to get anything burn on to the jug ,but this will happen, scraping, abrading and rubbing with anything could wear or damage the surface of the jug so its best not done.The process of polishing is rubbing a surface with finer and finer abrasive until the surface reflects the light/gets clean, it is wearing the surface which is why items such as jewellery eventually wear away, loose any engraving or patterns.
as far as i can remember andie its the same bicarb soda we have here in france and i didnt think it would be abbrasive either...but couldnt comment as i didnt know for sure as i never use it in cleaning but know it is an old ingredient like vinegar in homemade household cleaning etc..thanks for posting