There is a good post on the official forums that describes a good farming spot for all you Khajiit lacking a Skooma Bubbler for their house.
https://forums.elderscrollsonline.com/en/discussion/343780/how-to-farm-khajiit-skooma-bubbler-design
Level Thieves Guild skill line to level 7 (farm spot is inside quest instance). Quest is "Forever Hold Your Peace" Continue quest until you're inside Hublajad Palace. Pickpocket the servants until you has your stuffs. Do not complete the quest or you will not be allowed back inside and will need a new character.