From my Japanese reading, I've learned the word 冷やかし, but only in a negative context, connoting that the window-shopper is wasting the salesperson's time. Might it also be used in a positive way? For example, if a shop assistant offers me help, can I decline by saying, 「冷やかしをします」(or maybe 「冷やかしです」; IDK which is better), or does it sound like I'm winding them up? If a friend asks me what I did in town, is 「冷やかしをしていました」 a reasonable answer, or is it tantamount to saying "I went and pulled faces at all the shopkeepers"?
冷やかし is basically negative, and saying "(私は)冷やかしです" to a shop staff is rude. In reverse, if a staff said "冷やかしですか" to you, he must be strongly irritated.
Saying "冷やかしでお店に入った" to your friend can be acceptable depending on the situation, though. Some shops have signs like "冷やかし大歓迎" so that people can enter the shop freely.