What exactly is a boozy preserved egg and how are they made?
Here's a (slightly abridged) translation of the recipe you found:


(i) Select clean and fresh duck eggs with even shells.(ii) Other ingredients: glutinous (sticky) rice, wine lees, salt, brown sugar etc.
(i) Soak the glutinous rice in water - 24 hours at 12C, an hour less for every 2C increase in temperature.(ii) Drain and rinse the rice. Steam for 10 minutes, then sprinkle on some water. Steam for 15 more minutes, give it a mix, then steam for 5-10 more minutes.(iii) Rinse the rice with cooled boiled water to cool it down to 28-30C.(iv) Mix the lees with the cooled rice, and pack it into a fermentation crock. Sprinkle a layer of lees on top. [Using a rolling pin or similar,] create a deep hole in the middle of the rice. When the hole is filled with liquid, mix everything together. Age for half a month.
Using a piece of bamboo [or a spoon], crack the eggs very gently, making sure not to break the membrane.
(i) Sterilise a fermentation crock by steaming it.(ii) For 100 duck eggs: prepare 5kg rice wine [made in part 2]; 0.8kg 65% alcohol baijiu; 0.8kg brown sugar; 20g each of dried tangerine peel, star anise, and Sichuan peppercorns; and 1kg salt.(iii) Combine the rice wine, the baijiu, and the salt and layer the mixture with the eggs in three layers and store at room temperature.
(i) Remove the hard eggshells.(ii) Soak the eggs in baijiu for 1-2 days until the egg white/yolk solidifies.(iii) Add the sugar and spices from before to the fermentation liquid, then add the solidified, peeled eggs back.(iv) Age for 3-4 months, stir, then age for a further 2-3 months, after which they are ready to eat.


As you can see, this is a very long and involved recipe. What you're doing in step 2 is basically making fermented rice or laozao- here's a good guide on how to make this. It's also very similar to Dunlop's description, so I think it's very likely that those videos you found are of what she's describing. You can see the shells have been removed to leave the membrane, creating a sort of &quot;soft-shelled&quot; egg. It's certainly possible to make at home, but quite complicated.