You can also try these related scripts:

• SteamTrades - Have List Filter - Check if you own the games from someone's have list (instant Compare2Steam)
• SteamGifts - Hide Blacklist Giveaways - Hide Giveaways on SteamGifts created by users you blacklisted.
• SteamGifts - Remove Unwanted Entries - Adds a button that removes entries from giveaways of owned steam games you entered
• SteamGifts - Giveaway Error Link - https://www.steamgifts.com/discussion/VuO2j/the-link-in-you-dont-have-permission-to-view-this-giveaway-should-point-to-the-game-page-on-steam
• SteamGifts - Group Info Hover - https://www.steamgifts.com/discussion/7TeLS/script-request-groups-hover-identifier