Yes., clearing out what you don’t need/use is a good tip and one I need to take on board too :)
Look at low space items: concentrated clothes conditioner, boxed wash power takes up less space than tablets (per wash - and cheaper!). Concentrated orange squash and washing up liquid.
Focus on essentials: forget the dishwasher (if you have one) as all the supplies for that are more expensive and take up more room than a bottle of concentrated washing up liquid. Same with shampoo: look for a 2-in-1 or forget conditioner. Multipurpose cleaner rather than loads of different bottles of cleaning stuff.
Top/bottom of the wardrobe, under the bed, behind books on a book shelf, hanging baskets for inside kitchen units. Take stuff out of packaging where possible - freezer stuff is an easy one to remove the size of, just cut out the cooking instructions and stick it on the front of the polythene/freezer bag.
Reuseable baby wipes and make up wipes are quite cheap and easy to manage: personally I couldn’t handle washable nappies but Aldi have them on offer at the moment.
If you are really stuck for space you could use boxes filled with stuff as coffee tables/bedside tables etc: either covered in a cloth or using actual nice boxes (quite cheap in The Range/Home Bargains etc).
Have some sweets/crisps/treats: you can usually pick them up cheap and they last for ages. Same with cheap fresh orange (although I use it and dilute it so it goes even further!).
If you have 3 days aim for a week, and then try and build up to 2 weeks and so on.
Don’t take out a loan though!