I do not recommend doing anything that you feel is wrong.
You comment is noted, but obvious.
Here's my thoughts:
In business, selling a shredder only needs a small disclaimer. It needs to be worded correctly. It's done all the time. If it comes with a warranty, that too needs a disclaimer (if or when it might be returned for whatever reason).
On the customer side:
Using a shredder is commonsensical. If a person cannot figure out something so simple, they either a). had no upbringing, or b.) they were raised in the woods by a pack of wolves.
Cleaning a shredder is not-so-commonsensical. Rubbing alcohol, hot vodka, scalding water, etc. have all been floated around the internet. Re: water itself, is it hard water? Is it well water? If it's treated with a water softener (a decent amount of homes are) then 95% of all water softeners rely on salts (we had to pour big bags of it into our well tanks in the country, etc.). Other city homes have smaller water softener "units" that still run off of salts, and salts are the last thing you want around shredder blades or gears.
One thing I know with certainty is this. When I was in my younger years, we had to clean our "water pipes" from time-to-time [insert smiley face here], and one thing that always did the trick (from the resin/gummy stuff) was a product we have in the States called "Goo Gone" - many here know what this is. It's just an extract of heavy citrus. Lemon juice does the same trick. Any housewife knows this when cleaning greasy, gummy crap that's been 'baked' on things.
After thinking about this for a while tonight, it's obvious there's never going to be an answer on the business end. Writing up some cleverly worded disclaimers would solve this dilemma that businesses run into depending on the product they sell.
The best way to solve this is to actually pretend you - yes you -
are the gummy stuff. What you be your enemy? What would it take for you to let go of those blades, while keeping the integrity of the blades in perfect condition? What's your Kryptonite?
One thing's for sure, you would only use distilled or purified water,
that's commonsensical. Depending on the TDS in your tap water, or the amount of hardness (think calcium and magnesium), this would/could have a detrimental effect running it through the blades - especially if treated with salts/softeners.
If anyone has seen these blades through a microscope, one can see the invisible-to-the-naked-eye wear & tear the blades go through over time. Some of the dark tobacco varieties, fire cured, etc. have an obvious feel to them in the hand that anyone will know right away is going to sooner-or-later gum up that machine.
Common sense is really a moot point here. What should be talked about - especially in the type of forum and the topic it represents - are solutions. If there is anyone reading this that would like to brainstorm actual solutions, let me know. From a business standpoint, this can easily be fixed. Talk to the makers (usually a friggin Chinese company), or explain how to clean from personal experience alone, and write up a couple of disclaimers before the sale, and be done with it. A product of this nature obviously cannot come with an "All Sales Final" disclaimer, but what it can do is explain how to clean it, then add a disclaimer at the bottom of the instructions.
My "water" points above should also be mentioned because one home's water is not another home's water.
Mission accomplished = happy customers