In *Kingdom Come: Deliverance 2*, the side quest "A Good Scrub" leads to a series of bathhouse-related quests, culminating in the task to find something infested with fleas for Betty. Here's a comprehensive guide on how to complete these quests and find the flea-infested item.
Pick Up 'A Good Scrub'
To initiate the quest, speak with the innkeeper in Kuttenberg about work, who will direct you to Betty at her bathhouse in the southeast part of the city. Approach Betty and express your interest in work. She'll task you with fetching Matsek from Grund.
Upon arriving in Grund, find Matsek near a courtyard. He's apprehensive about being seen with the girls intended for the bathhouse. Locate the three girls at a nearby table, inform them you're there on Betty's behalf, and accompany them back to Kuttenberg.

Promote the Bathhouse
After safely returning the girls, Betty will need your help to attract customers to the bathhouse. Work with her to craft a promotional spiel, then head out to shout it at the grain market, horse market, vintners' street, and merchants' street. Ensure you do this during the day to maximize your reach.
Clean Up the Bathhouse and Finish 'A Good Scrub'
Once you've promoted the bathhouse, it's time to clean it up before the alderman's inspection. Completing these tasks promptly is crucial; failure to do so will result in the bathhouse being shut down, preventing you from picking up the subsequent quest, "Ill Repute."
Finding Fleas for 'Ill Repute' in Kingdom Come: Deliverance 2
After successfully passing the inspection, speak with Betty about ongoing issues. She'll reveal that the city council is deliberating on the main bathhouse. Your goal is to make the councillor leave the competing bathhouse by learning his dislikes from Meaty Mary, Katcha, and Little Lida.
To proceed, you'll need Chamomile Brew to spike the wine cask on the second floor of the rival bathhouse. Additionally, Little Lida will share that the councillor enjoys fragrant oils, but only after you gift her a noblewomen's dress from a tailor. If you choose to sabotage, lockpick a cabinet on the third floor and steal the oils.
Katcha mentions the bathhouse once had fleas. To obtain the flea-infested item for the quest, head to the east gate of Kuttenberg City. There, you'll find a small camp of beggars. Search the sacks to locate a flea-infested blanket.

Return to the bathhouse with the fleas and head 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 tasks (Chamomile Brew, fragrant oils, or fleas) is sufficient 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.*