A bidet and a toilet with toilet paper. I'd find a bidet confusing and awkward.
Upsells are useful. You make the assumption they only serve the company. This is wrong. Take for example the last upsale I purchased. I bought a Kindle. Amazon upsold a case for the Kindle before the checkout.
Apple pushes upsales all the time as well. I challenge anyone to go by a Mac in an Apple store, and try to buy it without having to mention to have the sales person discuss MobileMe, AppleCare, or OneOnOne.
You make the assumption that upsales are annoying and are obstacles. That's not true. The design of upsales can be made an obstacle or annoying, but then, I could argue the same about anything. Heck, I could take a blank page and turn it into an obstacle.