Actually using AI gibberish for this might be the best strategy of all, since Reddit seems hell bent on making money with AI training and feeding AI generated text into AI training has been shown to yield increasingly worse results over time. So you make the product Reddit is selling less attractive.

Do you mean oldest as in invented the longest time ago or oldest as in that specific technological artefact that i use is the oldest one i have?
For the first one i guess cooking?
For the second one its definitely my microwave oven, made in 1991.