Hey @carrianne 
As the others have said, itās not about need - ask yourself, do I want a charging plate? Personally, I didnāt want one and didnāt think I needed one, so like @Susurrus I bought small selenite sticks to put them in the pouch with whatever item (crystals, runes, cards) so they cleanse while theyāre resting.
However, I was in a spiritual shop and this small selenite bowl called to me, and I must say it is useful for cleansing many crystals at once, for example after a crystal grid. Also, I use it to cleanse any witchy items overnight, then in the morning I sound cleanse, just to make sure the only energy they are charged with is mine 
x Blessed Be x
Since you opened the box on real/fake/misnamed crystals,
I wanted to add this post on Satin Spar vs Selenite to the list.
Can open, worms everywhere 
Now Iām going to see if we have any others for common stones.
Edit:
I found these too @Artemisia
Physically Cleansing Crystals: Save this Chart! 
Does Selenite dissolve in water?
I use Selenite all over
I have bowls, plates, wands, a spiral tower, athame, slabs/pieces/bars. I use them all around my space & in my box where I have some stored.
I will put crystals, jewelry, runes, & other items on them too. I have clear quartz pieces near them & around my room.
I do the same with smaller pieces & keep them in my crystal pouch for the day. A small piece of selenite & a small piece of clear quartz with any stones, runes, charms, or whatever is in there too @Nikki-Phoenix! I keep a piece of clear quartz with my decks & selenite because right now they are all in a bag still in my room. I need someone to go downstairs with me so I can put them away properly 