In *Kingdom Come: Deliverance 2*, the side quest "A Good Scrub" leads to further bathhouse-related quests, one of which requires you to find an item infested with fleas for Betty. Here's how you can complete this task effectively.
Initiate 'A Good Scrub'
To start, speak with the innkeeper in Kuttenberg about work, and they'll direct you to Betty, who owns one of the two bathhouses in the city. Betty's bathhouse is located in the southeast part of Kuttenberg. Approach her and express your interest in the job she has available. She will then send you to Grund to find Matsek.
Upon reaching Matsek, you'll find him hesitant to be seen with the girls he's supposed to escort back to the bathhouse. Go to the courtyard where he's standing and locate the three girls at a table. Inform them you're there on behalf of Betty and accompany them back to Kuttenberg.

Promote the Bathhouse
After returning with the girls, Betty will ask you to help promote the bathhouse by spreading the word. Work with her to craft a promotional spiel and then shout it out at various locations: the grain market, horse market, vintners' street, and merchants' street. Make sure to do this during the day to attract the maximum number of customers.
Clean Up the Bathhouse and Complete 'A Good Scrub'
Following the promotion, you'll need to clean the bathhouse thoroughly before the alderman arrives for inspection. Completing these tasks swiftly is crucial; failure to do so could result in the bathhouse being shut down, preventing you from picking up the subsequent quest, "Ill Repute," from Betty.
Finding Fleas for 'Ill Repute' in Kingdom Come: Deliverance 2
Once the bathhouse passes the inspection, speak with Betty about the ongoing issues. She'll mention the council's decision on which bathhouse will be the main one in the city. To sway this decision, you need to make the councillor leave the competing bathhouse. Start by gathering information about his dislikes from Meaty Mary, Katcha, and Little Lida.
To sabotage the competing bathhouse, you'll need Chamomile Brew to add to their wine cask on the second floor. Additionally, you can learn from Lida that the councillor enjoys fragrant oils, but she'll only share this after you give her a noblewomen's dress from a tailor. To further disrupt their operations, lockpick a cabinet on the third floor and steal the oils.
For the flea-infested item required for the quest, head to the east gate of Kuttenberg City. There, you'll find a small camp of beggars. Search the sacks in this area to find a flea-infested blanket.

After obtaining the fleas, return to the bathhouse and go to the room where you added the Chamomile Brew to the wine. When no one is watching, interact with the baskets in the room and pour the fleas into Councillor Naaz's laundry basket and the clean laundry basket.
If you're unable to find the flea-infested item, remember that completing just one of the three sabotage tasks is enough to make the councillor leave, allowing you to complete the quest and move on to others like "Axe from the Lake."
*Kingdom Come: Deliverance 2 is available now on PlayStation, Xbox, and PC.*