How to build a custom loop activity in Elsa workflows

Question

I'm trying to make a custom activity that will eventually do a complicated database query or API call to get a bunch of records and loop over them. I'm sure it could be done with the built in flow control activities, but I want to make this usable by non-programmers who don't know or care what a foreach loop is, so putting a lot of functionality into one box is good.

My first attempt was to inherit from ForEach and do some initialization before letting OnExecute do its thing, but the result feels somewhat hacky.

public class FancyForEach : ForEach
{
    private bool? Initialized
    {
        get
        {
            return GetState<bool?>("Initialized");
        }
        set
        {
            SetState(value, "Initialized");
        }
    }

    protected override IActivityExecutionResult OnExecute(ActivityExecutionContext context)
    {
        if (Initialized != true)
        {
            Items = GetThingsFromDatabase();
            Initialized = true;
        }

        return base.OnExecute(context);
    }

    protected List<DatabaseThings> GetThingsFromDatabase()
    {
        // Fancy stuff here, including paging eventually.
    }
}

It seems like it would be a little cleaner to instantiate a ForEach somewhere within the activity rather than inherit from it, but I can't puzzle out a way to make that work. I imagine a decent solution would be to trigger another workflow for each record, but I'd rather not do that, again to make this easy to digest for people who aren't programmers.

Can anyone offer a suggestion on the best way to make this work? This is my first project using Elsa, so maybe I'm approaching it from an entirely wrong direction!