mixed, blended, mix, mingle
雜 centers on things being mixed or blended together, not kept separate. The core idea is mingling different elements into one combined whole.
雜 is the older traditional form of 雑. It combines 衣 (clothing) with 集 (gather), suggesting the idea of different fabrics or threads being mixed together.
The left side looks like a garment (衣) with many threads gathered (集) on the right. Picture a pile of mixed fabrics and threads all blended together.
For ザツ, imagine a mixed bag of zany zats: zats -> ザツ, and the kanji shows all those odd items mingled together.