The type of filter I shared above I use for water heater only.
For bathroom basin, kitchen sink and washing machine I use other type, but from same seller.
Installation is easy, just use adjustable spanner.

https://detail.tmall.com/item.htm?id=545891413663

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For washing machine you can take a look at this:

https://detail.tmall.com/item.htm?id=552128455083

Seems like I finally found a dispenser, made in Korea, ordering a sample now

Sure it is possible, I even asked if this would actually be beneficial, few pages ago, response was actually negative, saying it doesn't really help.

I would love to do that, but I would rather not take tap water, but  highly contaminated water and pass it through FD, maybe film a video of how it all happens, test "before and after".

Just sending a random sample claiming it comes from FD is probably not a fair game. What if I just took it from bottled water for example, if you see what I mean.
Edit: maybe someone would have an idea of some contaminants they want to test again, then we can contaminate the water on purpose and measure the performance of the filter in a lab