Willingness and resolve to sacrifice/ lose the things you love for God's sake is for God's gain. When you have this kind of intent to things, tithing included, God will bless you, i have experienced it too many times to count. Rather than destroy or delete them put them in a box or something and put them away somewhere for a while, while having full resolve to get rid of them if called to do so.
At the same time focus on God and learn that He is more valuable than those things. The creator is always greater than the things created, and things created is usually the thing man chases and idolizes. You can have and enjoy them, but be ready to dump them at any time if He says so. Having the mindset to have the intent to do that is an active expression of love for God. I know many who claim that they "love God with all of their heart", yet they can't even give the smallest things because they are too deep in their comfort zones, and they think love is just an emotional thing.
While you have your things put away, ask for a sign or something to let you know to get rid of them if it is His will. Also pray about it, and let Him know that you are ready and fully committed to get rid of them if you do get a confirmation on it. If you don't get a response after a few days, just put them back, and be resolved that He is fine with you having them. And when you do take them back, keep the mindset that He could still call and ask for them at anytime, so keep your offerings to Him still on the table.